The study is behind the original target to complete enrollment by February 1998. This was due to the 50% increase in study size and lack of success in several recruitment strategies. Recruiting strategies were revised in November wth a resulting substantial increase in potential volunteers. The study has been able to randomize 189 subjects into the intervention phase of the study following screening and baseline testing. The purpose of this study is to determine the effect of a home-based exercise program on bone mineral density of women using estrogen replacement therapy for 2 or more years. Women between 60 and 78 years of age who are currently using estrogen replacement therapy and have a low bone mineral density are eligible to participate in the three year exercise program. The twelve-week pilot enrolled twelve women whose bone density was too high for the study. Volunteers performed all exercises in the lower extremity training program, and most of the exercises in the upper extremity program. The pilot intervention allowed us to fine tune all aspects of the intervention. We confirmed that an exercise leader/volunteer ratio of 8:1 was optimal. 173 subjects are currently exercising in the exercise intervention phase of the study. The subjects have been able to increase their resistance (waist belt weights and Therabands) at the projected rate. The exercisers report good compliance with exercise sessions they complete at home as well as attendance in classes. The study was able to randomize 189 volunteers into the intervention phase and will be able to complete the study as projected. The subjects have responded very positively to the exercise program and are working diligently.